The mail must go through – and the same is true of the power cables! St Georges Road in Avondale is flanked by stately trees which I believe to be Queensland Box trees (Lophostemon confertus, Tristania conferta). It is amusing to see the huge cutouts which make room for the power lines on one side of the road.
The cutouts are visible in Satellite view of Google Maps!
The trees on the opposite side of the road have grown without interference, as seen below.